As Fred Ligon shared photos of himself serving abroad in Afghanistan, he encouraged students at Roanoke Avenue Elementary School to try on his camouflage uniform and helmet — complete with a night-vision monocle.

Mr. Ligon, who works as a Riverhead High School security guard, joined the Marine Corps at 17 and then went into the Air Force, where he spent the majority of his career serving with the Military Police.

“How did you eat when you were there?” a student from Hope Kaufmann’s class asked him.

“Here, I’ll show you,” Mr. Ligon said, as he picked up an MRE or meal, ready-to-eat bag and passed it around the room.

Mr. Ligon was one of three veterans who discussed their experience in the armed forces with third-grade students Friday morning in honor of Veterans Day. Veterans Brian Mooney and Barry Gilmore also spoke to the students at Roanoke. Additional lessons were held at Aquebogue Elementary School in the afternoon.

Mr. Gilmore, who served in the Army from 1966-1968 during the Vietnam War, explained that while he was out in the field, he had to surround himself with sandbags before falling asleep as a precaution.

During his nine months overseas, he was wounded in action at his base camp and later discharged. He received a Purple Heart for his service, which he showed to students.

“I was rudely awakened in the morning by the enemies dropping rockets on us,” he said. “When they explode, it’s a lot of metal fragments called shrapnel are released. It could have been worse, but I was hit.”

Mr. Gilmore, the father-in-law of Gary Karlson, who helped bring the veteran visitation to fruition about three years ago, said he visited the classroom to make sure students remember the efforts of veterans.

“I just feel it’s important for the kids not to forget veterans, what they did and why they observe the freedom that they have today,” Mr. Gilmore said.

Mr. Mooney also served in the Army during the Vietnam War. He completed 25 years with the military and four years with the National Guard.

The veteran said he returned to Roanoke for the third consecutive year to remind students that veterans fought for their freedom.

“Freedom is not free without somebody standing up to protect them and to insure that they have the right to have the opportunity to go to school without anybody bothering them,” Mr. Mooney said. “That’s what’s great about America — at least we have a chance to show these children that they have the opportunity to grow up free.”

Kate Nalepinski is a general assignment reporter primarily covering education on the North Fork. She’s a 2018 graduate of Ithaca College and has volunteered with the Robert W. Greene Summer Institute for High School Journalists at Stony Brook University.